I found a 4"x4" wet spot on my cabin floor (89 Larson San Marino). Floor appears solid and is carpeted. Hull looks fine and applied barrier coat 3 years ago. Wet spot is at foot of stairs and centered on the floor. Everything around it is dry though. I'm thinking of cutting into it to see what's going on and hope to install a deck plate when done. Anyone come across this before? Where can I get prints of the floor to ensure I don't cut into the stringers?